Affine Kac-Moody Lie algebras as torsors over the punctured line
arXiv:math/0203277
Abstract
We interpret and develop a theory of loop algebras as torsors (principal homogeneous spaces) over Laurent polynomial rings . As an application, we recover Kac's realization of affine Kac-Moody Lie algebras.
8 pages Corrected some typos and changed some notation. Minor generalization of one result